Effectiveness of microwave processing approach and green blowing agents usage in foaming natural rubber

This study mainly concerns the role of foam heating process techniques and its impact on cellular micromorphology, density and gas liberation mechanism of natural rubber foam with distilled water as blowing agent. Three different modes of heating process techniques and varying amount of distilled water have been examined on the foam density and cellular morphology, having rather identical morphological formation, cell distribution and relatively reducing densities but significant cell wall thickness. It is deduced that the increase in the water loading substantially affects the decrease in the foam densities, cell uniformity and stability. However, the heating process techniques influence the cell distribution and stability more than the amount of water content loading. The combine microwave oven process technique has improved the process of moisture diffusion into the water-blown open cell natural rubber foam unlike the slower procedure of conventional heating technique. In addition, the natural rubber foam physical properties and microstructure is improved better than the conventional heating technique. In all the simultaneous combine microwave oven technique is the best among the evaluated technique from the experiment because of density increment, cell distribution, pores flaccidity and uniform cells.